Sound emitting system



Aug. zo, 1935,A

C. L. FLORISSON SOUND Original EMITTING SYSTEM jyG/Z 29 42 M M V55% 5.5' ,i I 5^ Y f L k 'a a 5a 4459 40 56 i z Patented Aug. 20, `1.935

UNITED STAT- Esi PATENT- OFFICE. Y

Y soUND E'MlrrrNG' ,sys'ilun-' I Charles Louisloi-isson, Courbevoie (Becon-Les- Bruyeres), France, assigner of one-half Vto' Societe de L'Conden'sation. & d applications ,.Mecaniquea Paris, France, a corporation of Y,

France f f original appiioauoilrebrary' 2v, 1932, seriaiNo. f '7 595,640. Dividedvand this application'-Deceni-k ber i6, 1933,1'Serial'No. 702,779. In France July lThis application is adivision of my copending application Serial Number 595,640, filed February 27, 1932. d My` invention relates to apparatus. including 5 a sound emitting device adapted tovbe operated by a gas under pressure and which is intended to produce a short but strong soundfsignal, `and more especially to air Wave echo apparatus such as can be used on aircrafts for determining the altitude.

.It can readily be ,understood that in such'apd reflected sound Wave, 'especiallyV when the altitude j is low. This necessitates that a small'volume of compressed gas should be -suddenly fed to'fth'e sound emitting device. Such a result is somewhat difcult to obtain ,due tor .loss of pressure lin the pipes through 'which the compressed gas' 'is fed tothe sound emitting device and tof the more or less considerable lVolumelof'said pipes. f `The object of the present invention is to prov ide anapparatus ofthe .type above referredto whichY permits the emissionof .strong and .shortfsound l signals. f

To,V this.A effect, 'accordingv to my invention, V'a chamberpf small volume containing the'volume.

of'gas required for a single emission-is inserted in the pipe through Which gas underpressure isfed to the sound emitting device. This elianrkv ber is connected, on one side, through a narrow l nozzle or tube, With'said feed pipe, and,'on Vthe other side, throughA a shortV conduit offlarge section, With the sound .emitting device, avalve controlling theilovv of gas .through said conduit. l Other features of the present invention `will 40 appear from the folowing detailed description thereoffl l I l Y vA preferred embodiment ofthe presentv invention will be, hereinafter described -with refer.- ence to the'accompanying,drawing-,given lmerely 45,` by Wayof example, and rin which: f v v Fig. 1 is a diagrammatic view of an acoustic sounding apparatusembodying the present inven-V tionfan`d y j Fig-.2 is a diagrammatic sectional "View vofthe valvedevice utilized in Asaid apparatus. l

Adverting t'o- Fig. 1,?on the tube 28 through Which gas under pressure' is fed tofthev sound emitting device Il', there isdisposed, immediatelyv p before valve 2te, a small chamber 29'fthevolume of which isso chosen as-'tocorrespond With 'the j sdrclafoois. (012177148) output of the emitting device andwhich must contain areserve of gas necessary for a single short emission. This chamber is fed with com# pressed gas through pipe 28, with the interposition of'a tube 1 of restricted section 3B producing a 6 loss-'of pressure at that place. "On the contrary theconduit leading from chamber 29 to'sound emitting; device il ismade short and of large section y'so astoavoid anyloss of pressure 'at f that piace and vlocalize the losses of' pressure in l0 theemitting device itself, as it is' desirable. With such kan arrangement, the fopening of valve 20 produces the instantaneous discharge of chamber 29 into the sound emitting device'and the time AIter-*Which the emission takesplace is only a func- 1I ,tion of the volume `chosen for chamber 29,' the pressure of vthe gasjand the sections of the openings'ofthe er'nittingftube.v The inlet'of'this chamber 29 'is ofsuch a vsmallrsection that vthe Vjet of Vgas that "-pass'esftherethrough when the 20 emission is endedjcannot operate the sound emitting device. Blut it YshouldhoweverfbeV large enough, once' valve-'28a is closed, to allow of chamber- 29 beingi'llled With gas at the pressure existing in tube ina sufficiently'short timefor 25 permitting av frequent repetitionof the emissions (namely with an interval of time betweenthe f emissions of about one second or ia few seconds),

. Valve Za must open extremely quickly when Contact' l4-l'6 is closed, and it is advantageousv to 30 utilize electric current -of low voltage and inten-AV sity.Y These conditions, Which are difcult'to ob- Y tain with ordinary electrically controlled valves, are. onY the contrary easilyv obtained with the arrangement hereinafter describedwithreference to Fig. 2.

. An obturaung piston a2 is adapted to sudo with l an easy! nt in a cylinder 3| directly connected with Ythe-sjoundemitting ldevice l1. The comlpressed air is introduced through orifice 33 con- 40 nected with a circularl groove 34 which completely surrounds ,theV piston;v With this arrangement, When'the piston is in the'position shown in solid lines in the drawing, it outsoif the connection' between compressedair inlet 33 and the vvibratory 45's lposition 35, shown in dotted lines inthe drawing,v

the compressed gas flows freely from. 33 itovvard In." 'It win be noted that the disposition of the 'Fie - sliIQkebeing, b, the wholestroke is a b) quick opening from the time when` said openings@ is started, by utilizingv exclusively, from that time the motive agent for f on, the compressed gas as driving the piston.

The movement of the pistonwmay be controlled through any device exerting oen-a .rod 3l, at the time chosen for the vibratory sound emission, a,

force, even relatively small, directed toward the left. I may utilize mechanical controls -comprising rods, shafts, or cables, pneumatic controls, hydraulic" controls, electric controls, 'electro magnetic controls and the' likefv I will now describe,` by 'way of non`limitative example, a controlling device including an electro-magnet.

` The electro-magnet may be of any type yWhatever, either ofthe ironclad typefor not'acting either directly jor through a multiplying arrangement, or again' through a device adapted to slow down the modification of the'magnetic yforce as a function of thedispla'cenientfn Fig. 2 I have shown, by"way`o'f example, an ironclad electromagnet 33'. 'VIhe'str'oke of movable part 39 may besochos'en as to be equal to the relatively small value ya abovefreferred to. WhenV `current is allowed tofl'w'though the electromagnet, the

movable core 3Q isdrawn toward the left, driving rod` 4dftogetherV with it. `At right hand end the latter"v is'bifurcated, as shown,V and is laterally slotted or formed' 'with` a houow laterally slotted einlar'ged'sternA similarlyvarranged so as to allow of rodv 3l sliding loosely therein. This rod Slis] DOV'dedfWih a Siep, Sllh as pin 42 for instance, engaginginthe elongated slot or slots entitledistiefrihfheiuendtfred 4.o. when the latter riiffl., @Walid the left it Causes` rod 3.1 Mt move together with it, stop 4Z abutting liisi, ih? iight han@ en@ 0f. the, Slot or, slots. lfli, ODreiQil iS OUOWSI The..electromaenet l .Causesiis mevablrart SS, and therefore piston 3,2 tamevevrward a distance equai to a, which imiiaies. the Opening. of port 3.3... when the movable part oftheelectromagnet is atthe end of. its stroke toward the left, the suddencompletionof (t the Vopening ov the port is obtained, as above explained, by the action of the compressed gas on the ,rightl hand; face of the piston., The piston is suddenly driven towardV the left. until. it 'comes intqcontact.,withshoulder 33 v(that part of its In order toallowsuch anoperationof the parts, rod 40 is provided with axhollow part 43 Whose length is very slightlygreaterthan b. A` spring 44 of suitablestrength, bearingon the one hand against a stationary part fixed to the frame ofthe electroi as the. pressure at l-lhas droppedto a low value (endof'thelemission of the sound-signal) YSaid springthendrivesr the whole off the piston and of movablespart :39 of the electromagnet, whichY are now connected togetherthrough pin 4,2-, 'with aV displacement equal to a toward the right (closed position) as soon as the current flowing through the electromagnet has been cut oiT.

The above description clearly shows that, through the combination of valve 20a, built according` to the principle illustrated in Fig. 2 and of a chamber 29 provided with the narrow nozzle Aor tube Sii, the short vibratory sound emission can be started by causing, at a determined moment, an electric current, which may be of relatively low intensity and voltage, to pass for a very short time, through electromagnet 38, said electromagnetbeingintended merely to displace ,the pistonso as to partly uncover port 33, the complete openingbeing then suddenly produced through the action of the gas pressure. The

'stoppinglof the emission is automatically produced when chamber 29 is emptied and the gas pressure on the right hand face of the piston has become lower V than the compressive force exerted by spring 44. Said spring then pushes piston 32 to- Ward the right and thus cuts off the reduced jet of gas issuing through 33 and stops the vibratory emission (contactv lli-IS is so adjusted that the current is switched off before the end of the sound emission, that is to say before chamber 29 is emptied). e

@Any known' means may be provided yfor adjusti-ng the force exerted by spring 44 on piston 32 so as to permit of the sound emission being cut off whenY the pressure in chamber 29 has dropped to a certain value, in order to permit of shortening-the duration of the emission for soundings. at very short distance. Y-

VWhile I have described what I deem to be -a i practical and eflicient embodiment of my invention, it should be well understood that I do not wish. to .be limited thereto aswthere'might be changes made in the arrangement, disposition and formv of the parts without departing from the principle of my invention as comprehended within the scope of the appended claims.

l. Anv apparatus of. the type described, which comprises in combination, a sound emitting device of the Wind instrument type. operative by a gas under pressure, means for feeding gas under pressure to said sound emittingrdevice, a Achamber of small volume adapted to contain the quantity of gasrequiredfor ashort `emission of said'de- Y vice, aY nar-row passage betweenrrsaid means and said chamber; ashort. conduit of large sectionrfor iorming4 a passagehetween said chamber and said sound emitting device, and valve means-for quickly f ully opening the passagev betweenisaidcha'mber 1 and saidl sound emitting device. e

Vfor controlling thelconnetion between said con-Y duit and said sound emitting device, said piston valve havingone of `its ends constantly connected with Sai-d, Sound emitting device, and contra means for bringing said-piston valve, into a Apartly open position, whereby` said end of the piston valve is subjected tothe action of said gas under pressure which quickly flully opens it.

3.. An `'apparatus of the type describecl.,. which i ingfdirectly into said conduit, a piston adapted to slide in said cylinder, an electromagnet including a winding fixed with respect to said cylinder and comprises in combination, a sound emitting device of the wind instrument type operative by a gas under pressure, means for feeding gas under pressure to said sound emitting device, a vchamber of small volume adapted to contain the quantity of gas required for a short emission of said device, a nozzle of restricted section connecting said means and said chamber, a short conduit of large section connected with the outlet end of said chamber, a cylinder directlyV connected withY said sound emitting device and provided with an aper-V ture in its wall opening into said conduit, a piston adapted to slidein said cylinder, control means for starting the sliding displacement of said piston as far as the position thereof for which said aperture is partly uncovered by said piston, so that the full displacement of said piston is subsequently ensured by the gas pressure, and elastic means for vurging said piston toward its initial position. f

4. An apparatus of the type described, which comprises in combination, a sound emitting de- Y vice or the wind instrument type operative vby a gas under pressure, means for feeding said gas under pressure to said sound emitting device, a

chamber of small volume adapted to contain they, 'quantity of. gas required for a short emission of said device, a nozzle of restricted section connectingsaid means with said chamber,V a short conduit of large section directly connected with the outlet end of saidchamber, a cylinder directly Vconnected with said sound emitting device and provided with an aperture in its lateral Wall opena core movable in said Winding parallel to the axis of said cylinder, `means forconnecting said piston with said core witha certain axial play, elastic means for urging said piston toward its position with respect to said cylinder in which it covers said aperture in the cylinder wall, and means for energizing said electromagnet, whereby the energizing of the electro-magnet causes v the core thereof and therefore the piston to move against the action of said spring, thus partly un,- covering said aperture, the complete and rapid Vopening then taking place under the eilect of the gaspressure in said chamber, while the closing displacement of the piston is effected by said spring, as soon as the strength thereof is greater than the force exerted by the remaining gas 'pressure on the piston.

5. An apparatus of the type described, which CHARLES LOUIS FLORISVSN. 

